1. Field of the Invention
This invention relates to a keyboard musical instrument, wherein the mechanical vibrations of the strings connected to the key units are converted into musical tones after electrically picked up.
2. Description of the Prior Art
A piano is a known keyboard musical instrument, but is too heavy to be easily carried. To make up for the shortcomings of the ordinary piano, there has recently been developed an electric piano as a portable keyboard musical instrument resembling the conventional piano in respect of the musical tones produced as well as the method of playing.
The electric piano is provided with mechanical sound generators such as tuning forks and reeds corresponding to the respective tone pitches. Upon key depression, a key unit is actuated to strike a generator having a tone pitch corresponding to a key depressed, thereby generating a musical tone by the vibrations of the generator. These generator vibrations are electrically picked up to be sent forth as a musical tone through a loud-speaker.
With the above-mentioned type of electric piano, the sound generator is hit upon key depression, making it necessary to provide a hammer action mechanism like that used with the ordinary piano and consequently presenting difficulties in sufficiently simplifying the arrangement of the electric piano for miniaturization. For this purpose, the generator itself also has to be fully shortened. However, the generator thus shortened substantially fails to produce harmonics, though capable of providing a fundamental frequency corresponding to a given tone pitch, thus preventing a tone played on the electric piano from presenting a musical effect closely resembling that of the ordinary piano.
To eliminate the drawbacks of the tuning fork or reed used as a generator, it has been proposed to use a string. This process is to stretch a string having a prescribed length corresponding to a tone pitch with both ends fixed, strike the string upon key depression by a hammer action mechanism and electrically pick up the vibrations of the string. In this case, too, it is necessary to provide an action mechanism corresponding to a tone pitch obtained from each string. Therefore, an attempt to lighten and miniaturize the proposed electric piano is naturally subject to certain limitation.